lib/ro/cache.rb in ro-1.1.1 vs lib/ro/cache.rb in ro-1.2.0

@@ -1,20 +1,26 @@
 module Ro
-  class Cache < ::Hash
+  class Cache < ::Map
     def write(key, value)
-      self[key] = value
+      invalidate(key)
+      set(key => value)
     end
 
     def read(key, &block)
-      if has_key?(key)
-        self[key]
+      if has?(key)
+        get(key)
       else
         if block
           value = block.call
           write(key, value)
         else
           nil
         end
       end
+    end
+
+    def invalidate(key)
+      prefix = Array(key).dup.tap{|array| array.pop}
+      set(prefix, {})
     end
   end
 end